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The role of cell size in body size change in animals
Hájková, Věra ; Starostová, Zuzana (advisor) ; Frýdlová, Petra (referee)
Animals are very variable in body size. Differences in body size are visible not only at the interspecific level but also within species, whether they are differences in size during ontogeny or among individuals of the same species exposed to different environmental conditions. The size of the organism depends on the size and number of the basic units from which it is built, i.e. the cells. From this perspective body size can be changed only in three ways: by changing the cell size, by changing the number of cells, or by combining these two mechanisms. It is assumed that during development an individual can be affected by many environmental factors that can alter cell size and/or cell number. The most discussed one is the environmental temperature. Quite often, organisms that live or develop at low temperatures reach larger body sizes, and it was repeatedly found that the body size increase is associated with increase in cell size. In addition to temperature, the size and number of cells, and consequently the body size, can be affected for example by oxygen concentration or by quality of nutrition. Environmental factors can interact with each other and often it cannot be clearly stated that changes in size or number of cells are caused only by one particular factor. Although there is a clear need...
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Matter in Plotin's philosophy
Zajíček, Samuel ; Chlup, Radek (advisor) ; Němec, Václav (referee)
The diploma thesis attempts to present a consistent conception of matter in the philosophy of Plotinus. Its first part therefore contains a presentation of his own ideas about matter employing the interpretation of three key treatises dealing with this topic (Ennead II, 4 (12) "On the Two Kinds of Matter", Ennead III, 6 (26) "On Impassibility of Things Without Body" and Ennead I, 8 (51) "On What Are And Whence Come Evils"), the second part is dedicated to the overview and criticism of major modern interpretations of Plotinian matter. The third part then introduces my own approach, consisting of splitting Plotinus' hypostatis of soul into two hypostases, and identifying matter with the procession (i.e. proodic aspect) of the ontologically lower of the two. Arguments are offered for these nonstandard interpretive choices; the resulting conception is shown both as self-consistent as well as consistent with Plotinus' metaphysics as such, and it is demonstrated to be able to reconstruct the features that Plotinus attributes to matter.
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Factors affecting the composition of insect communities on carcases of small mammals
Máslo, Petr ; Šípek, Petr (advisor) ; Čížek, Lukáš (referee)
This thesis describes invertebrate community on cadavers of small mammals, in particulat how cadaver size influences abundace, density, species richness and composition of the necrobiont community. Cadaver size preference of present insects is also described. Field experiments were performed in 2014 in meadow habitats in spring, summer and autumn season. Cadavers were chosen in three weight groups: mice (20 g), small rats (100 g) and large rats (400 - 500 g). Invertebrate abundance increases with cadaver mass, density of the community remains constant. Larger cadavers also have higher species richness. Most dominant ecological guild are necrophages, represented mosty by blow flies (Calliphoridae). Cadaver size preference of recorded insects differ, necrophagous and predatory taxa tend to prefer larger cadavers. Omnivorous carrion beetles (Silphidae: Nicrophorus) prefer small cadavers. Sex of the carrion beetles (Silphidae) does not affect their cadaver size preference, males and females of particular species have very similar preferences. Keywords Ephemeral resource patch, cadaver, necrobiont, size, abundace, diversity, competition, insect communities
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Ecological determinants of plant clonal growth
Martincová, Nina ; Weiser, Martin (advisor) ; Latzel, Vít (referee)
The aim of this study is to provide a further insight into influence of environment on clonal plants. The study focuses particularly on effects of fertilization level and light availability on production and growth of clonal organs. Three experiments were carried out within the study, targeted to elicit influence of these environmental conditions or clonal interactions on six species of clonal plants. Interspecies dependencies on these conditions was compared, regarding habitat occurrence of these species. A comparison was made also between species producing rhizomes and stolons. The experiments revealed that five of six studied species show significant relationship among at least one environmental condition and parameters of clonal reproduction. Most of the species showed higher elongation and production of clonal organs in relation to fertilization level. On the contrary, only three species reacted significantly to the light availability level by alternation of at least one parameter of clonal reproduction and the light availability level affected each species differently. A strong influence on production and elongation of clonal organs had also a size of a plant. There was not found significant difference in influence of environmental conditions on clonal reproduction among plant families. It...
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Effects of pattern, size and background contrast of prey on discrimination learning in avian predators
Kuncová, Aneta ; Exnerová, Alice (advisor) ; Komárek, Stanislav (referee)
The topic of this master thesis was the effects of pattern, size and background contrast of prey on discrimination learning of avian predators. The aim of this study was to investigate the influence of selected components of warning coloration on aversive discrimination learning of avian predators of different age and sex. The choosen model organism was the Great tit (Parus major). The comparision was done between hand-reared naïve birds and wild-caught adults of different age and sex. The experiment was taking place in the experimental cage with one way mirror. The experiment used a design of simultaneous task with two pray which differed in one component of the coloration (pattern, size and background kontrast). The differencies in the ability of discrimination learning was found just between hand-rared naïve birds and wild-caught adults. Better results were shown by the wild-caught adults. The ability of discrimination learning of wild-caught adults was not influenced by the age and sex. Pattern was the only significant component of the warning coloration due to which the birds were able to memorise the discrimination task. Key words: avoidance learning, unpalatable prey, pattern, size, background, contrast
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Droplet size evolution during rain event
Kim, Yong Min ; Hovorka, Jan (advisor) ; Braniš, Martin (referee)
This work will focus on measuring the rain drop size distribution during several episodes of precipitation. From the data matrix a simplified graph - color contour maps were drawn. The dynamics of the size of rain drops during a rain will be linked to the type of precipitation and global movement of air masses from withholding episode.
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How predation risk affects the growth and development of dragonfly larvae?
PEROUTKA, Miroslav
Predation and prey responses to predators in aquatic environment are reviewed with emphasis on non-lethal effect of predators on prey life history, antipredator behavior and related mechanisms. The review focuses on dragonfly larvae and other groups of prey with complex life histories, mainly anurans. The review is complemented by laboratory experiments examining the effects of varied food availability and predation risk on a selected species of dragonfly, Sympetrum vulgatum.
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Trends in the Consumption of Coffee
PROVÁZKOVÁ, Eliška
The target of the marketing research in this work is to find out if there are some differences in the preparation of the coffee between users of various gender, age, education and a size of a place where they live. I used a method of questioning of at least 200 respondents. The next goal of this work is to find out what is for the consumers the most important shopping motivation, if they prepare and buy their coffee differently over the past years. Then I will write something about what they prefer - which brand, type, size of packaging. The theoretical part is about plantation of coffee, how coffee prepares, consumption of coffee in the Czech Republic and in the world, the culture of coffee, a creation of the market in the Czech Republic and a marketing research. The practical part mainly focuses on the research of the end user, sales research, research of product and prognosis. The practical part partly examines the total market analysis and the advertising research. The final part shows the current trends on the coffee market. It shows that over the past 10 years the habits in preparation of coffee has changed because the present trend aims at coffee express. The preferences concerning the size of the packaging has also changed ? coffee directs toward bigger package. The number of people who drink coffee and buy it in the hypermarket has risen. The biggest shopping incentive is the taste. The most preferred is the middle price level. Consumers most often buy the instant coffee in supermarket and in hypermarket. The most common preparation of roasted coffee is express coffee which is preferred by new consumers. Women do shopping in supermarket or hypermarket more often than men and women are more influenceable by an advertisement than men. More educated users prefer express coffee while less educated consumers prefer turkish coffee. More educated consumers more often visit hypermarket than less educated.
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Effect of stimulus size in discrimination and categorization processes in birds
NÁCAROVÁ, Jana
The mechanism of predator categorization has not been understood well yet. I examined how coloration pattern and predator size influence categorization by a prey under laboratory conditions. I tested the reaction of great tit (Parus major) to the plush dummies of sparrowhawk (Accipiter nisus), coloured as sparrowhawk, pigeon, robin and great tit. The same color variations were made in the sizes of a sparrowhawk and great tit. My results indicate that the coloration plays the main role in the recognition. The size is not important in the dummies coloured as the predator and the conspecific but it plays a role in recognition of other tested dummies (coloured as the pigeon and robin).
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